Google Outbound Services Configuration Guide - Manual (Page 105)

112 Outbound Services Configuration Guide
4. Confirm that your mail server is not an open relay. An open relay will make
your mail server vulnerable to hijacking from spammers and will most likely
cause an interruption in service.
Use an external open relay test, such as http://www.mxtoolbox.com/
diagnostic.aspx or http://www.spamhelp.org/shopenrelay/ . If the result
shows that you have an open relay, correct your private relay settings. If you
see an uncertain response (such as “maybe” or “warning”) then check that
your private relay settings are correct.
See “Set Up Reinjection” on page 108 for the correct private relay settings.
Troubleshooting
If you encounter delays or problems with using IBM Lotus Domino with Private
Outbound DNS, consider changing your Lotus notes settings. These settings are
listed in notes.ini. See your IBM Lotus Domino documentation for information on
how to change these settings.
Some changes to consider:
• Set the “Maximum concurrent transfer threads” equal to “Maximum transfer
threads”. Increasing the maximum current transfer threads can increase
bandwidth and prevent threads from locking up.
• SMTPErrorLimit set to 1.
• SMTPTimeoutMultiplier set to at least 11.
• SMTPMTA_DATA_TIMEOUT and SERVER_SESSION_TIMEOUT should be
removed or commented out.
• Disable pipelining. Pipelining can cause threads to become dedicated to a
single recipient address when used with Private Outbound DNS. This can
cause mail delays.
Also, increase logging for troubleshooting:
• SMTPClientDebug=1
This increases the amount of information logged, which will help find any other
problems. Once the problem is resolved, change this to its original setting.
How can I be sure my firewall allows a connection to Private Outbound DNS?
Your sending mail server needs to be able to reach the message security service
using DNS on UDP port 53.
If you are not sure your network settings allow your mail server to connect to an
external DNS host on UDP port 53, run the following test on your mail server:
1. In a DOS command prompt, type nslookup .
2. Note your current default server.
3. In the nslookup prompt, type set q=mx and hit return.